Closure for dispensing containers



March 1, 1966 H. D. WHEELER 3,237,817

CLOSURE FOR DISPENSING CONTAINERS Filed July 20, 1964 1N VENTOR. 194M040 .445 MESH-3Q United States Patent 3,237,817 CLOSURE FOR DISPENSING CONTAINERS Harold Dale Wheeler, 4321 Lennox Blvd., Inglewood, Calif. Filed July 20, 1964, Ser. No. 383,716 Claims. (Cl. 222519) The present invention relates generally to dispensing containers, and more especially to closure means for such containers which effectively seal or close a discharge opening to prevent leakage of the contents from the container or the entrance of air or foreign matter into the container.

Any closure means for a dispensing container such as a flexible metallic tube, a plastic squeeze bottle, or other container is not fully satisfactory unless it seals tightly the discharge opening from the container in a manner to completely prevent unwanted discharge of the contents of the container or undesirable entrance of air, foreign matter, or other substances. This capability requires that the closure member be brought into firm sealing contact with an engaging surface on the container and that the relationship between the closure member and the container be such that this firm contact is maintained at all times, even though movement or vibration may tend to destroy this contact.

Some of the simpler closure means, such as a cork in a bottle, have this capability to a high degree, but they suffer from the combined shortcomings that they are often times hard to remove from the container and, being separable, often are lost. On the other hand, the more sophisticated types of closure members, such as screw caps and the like, often are unable to generate the desired sealing contact between two surfaces or are easily moved to an open position by movement of the container, vibration, and the like, thus allowing the contents to discharge accidentally. Another practical problem encountered with many of the more complicated closures is the fact that the structure is either expensive or not sufliciently rugged to withstand the ordinary use to which it is subjected.

Thus it becomes a general object of the present invention to provide closure means for a dispensing container which effects a tight seal around a discharge opening so that leakage of the contents is avoided, even in the case of liquids or other substances which are difficult to retain, while at the same time shutting off access of outside air through the discharge opening to the container contents.

It is another object of the present invention to provide a closure member which is rotatably mounted on the container and which can be moved to a secure sealing position from a full open position by only a fraction of a turn, for example, one third to one-half of a turn.

A further object of the present invention is to provide a closure for a dispensing container which is adapted to a wide variety of containers, such as flexible tubes, plastic squeeze bottles, and other containers, and which is simple in construction and rugged so that its efliciency is not impaired through normal use.

A further object of the present invention is to provide a closure means having the above characteristics which, if desired, can be provided with a captive or non-removable closure member to avoid losing this closure member.

These objects of the present invention are attained by providing a dispensing container with a tubular discharge neck having external threads and having near the outer end of the neck a discharge opening which communicates with the interior of the container, said neck having a terminal external surface contoured so that the locus of all points in the surface at a given radius from the longi tudinal axis of the neck is a helix of one revolution having an axial pitch less than the pitch of said threads. The terminal surface on the discharge neck is preferably, though not necessarily, curved in an axial plane. The discharge opening in said terminal surface is eccentric with respect to the axis of the neck and is, therefore, in a surface inclined to the axis of the neck when the terminal surface is curved in an axial plane.

A matching cap is provided having an internal surface mating with the terminal surface of the neck and having internal threads engaging the external threads on the neck, the cap having discharge means movable into and out of registration with the discharge opening in the neck by rotation of the cap. -By providing the cap with a ramp cooperating with an oppositely facing ramp on the neck, the cap can be held against rotation suificient in extent to remove it from the neck while allowing a degree of rotation sufficient to open and close the discharge opening in the neck.

How the above objects and advantages of the present invention, as well as others not specifically mentioned herein, are attained will be better understood by reference to the following description and to the annexed drawing, in which:

FIG. 1 is a perspective of one end of a dispensing container with closure means comprising a discharge neck and a cap thereon embodying the present invention, the cap being in the open position.

FIG. 2 is a longitudinal median section through the discharge neck and cap on line 22 of FIG. 1.

FIG. 3 is a transverse section looking upwardly inside the discharge neck as on line 3-3 of FIG. 2.

FIG. 4 is a side elevation of the discharge neck with the cap removed.

FIG. 5 is a plan view of the neck of FIG. 4.

FIG. 6 is a longitudinal median section similar to FIG. 2 showing the cap rotated to the closed position.

FIG. 7 is a fragmentary transverse section on line 77 of FIG. 2 showing the locking means.

FIG. 8 is a perspective of the discharge neck with the cap removed, viewed from the right in FIG. 4.

FIG. 9 is a view similar to FIG. 6 illustrating a variational form of the invention.

FIG. 10 is a fragmentary side elevation of a variational form of locking means.

Referring now to the drawing, there is shown in FIG. 1 a container 10 which is representative of the type of dispensing container to which the present invention may be applied; such container may be, for example, a metal tube or a plastic cylinder, these being the more familiar types of containers having flexible walls which facilitate dispensing the contents. At one end of the container, it is provided with a tubular discharge neck 11 over which is placed cap 12. Discharge neck 11 is hollow, as shown in FIG. 2, and is in free communication at its lower end with the interior of the container 10 in order that the contents of the container may flow into and through the neck and be discharged through discharge opening 14. For reasons which will be apparent, discharge neck 11 is preferably circular in cross-section, but the interior space may be of any shape and the neck may be of any convenient length.

Discharge neck 11 is provided with external threads 15, as shown particularly in FIG. 4. In a preferred embodiment illustrated, the exterior surface of neck 11 is slightly tapered outwardly away from container 10, the angle of taper being relatively small and typically of the order of about 5 degrees, more or less. With a tapered discharge neck, it is preferred to use the buttress type of thread illustrated. However, the invention is not necessarily so limited and a V-shaped standard thread may be used instead; although it is preferred that in the event approximately .001 inch with respect to each other.

a V-shaped thread is used that the taper be eliminated and the exterior surface of the neck be cylindrical.

Outwardly on the discharge neck from threads 15 is the terminal surface of the neck which is one of the characteristic features of the present invention. Viewed in profile as in FIG. 4, the terminal surface 18 is preferably curved, though the tip may be more or less flattened, that is, the intersection of surface 18 with an axial plane is an are for most of its extent, as may be seen in FIG. 2. In addition to this curvature, the terminal surface is so contoured that the locus of all points on the surface at any given radius from the longitudinal axis 16 of the neck is a helix of only one revolution in extent. Since the helix is only one revolution in extent, the helix terminates at a shoulder 20 which lies in an axial plane, as shown particularly in FIGS. 4 and 8. The height or axial dimension of shoulder 20 is equal to the pitch of the helix. Although this axial dimension of the shoulder is constant across its full length, the shoulder disappears at the end of the terminal surface where the surface blends into the cylindrical or tapered configuration of the remainder of the discharge neck.

Cap 12 is internally screw threaded as may be seen in FIG. 2 with threads 15a which match in pitch and configuration the threads 15 on the outside of the discharge neck. Inside, cap 12 has an interior surface that conforms in all respects to the exterior surface 18 of the neck in order to provide an opposing mating surface which will engage substantially the entire surface 18. The internal cap surface has the same contour and pitch as surface 18 and also has a matching radial shoulder 21.

It will be understood that the surface can be cut with a thread forming tool, allowing the discharge neck to make only a single revolution with respect to the tool for any given cutting position. Thus each cut of the tool stops at the base of shoulder 20. In practice, the shoulder does not terminate at the geometric center of surface 18, that is, on axis 16. For practical reasons, it is preferred to form a small depression 23 (FIG. concentric wit-h axis 16 at the tip of surface 18 in order to facilitate formation of the external terminal surface. Also, it may receive a corresponding projection on the inside of cap 12 to stabilize the position of the cap.

The pitch of the helix at any point on surface 18 is less than the pitch of threads 15. For a practical convenience in manufacture, it is preferable that these two pitches differ by one thread per inch. By way of example, but without being limited thereto, a satisfactory construction is to make the pitch of the helix on surface 18 nineteen threads per inch while threads 15 are eighteen threads per inch. The reason for making a difference of one thread per inch .is a practical one since lead screws and thread cutting machines normally are designed to cut an integral number of threads per inch; but it will be obvious that this is not necessarily true when the metric system of measurements is used.

Giving the terminal surface this helical configuration with a pitch less than the pitch of the threads is comparable to a differential thread arrangement. In the assumed example, at nineteen threads per inch the pitch is .0526 inch, while at eighteen threads per inch the pitch is .0555 inch. The difference between these two pitches is .0029 inch so that as the cap is advanced axially along the discharge nozzle by threads 15, the differential axial motion between the internal surface of the cap and the terminal surface of the nozzle during the last turn is only the difference in the pitches. Thus it will be seen that for the last one-third revolution of the cap, the mating surfaces of the cap and the discharge nozzle move axially The sealing pressure generated between the cap and the mating surface 18 is in theory equal to that produced by a screw thread of 342 threads per inch, which is obviously too fine a thread to be practical for this use.

It is obvious that, in order to obtain this differential axial motion, a helix on the terminal surfacelS must have the same hand or inclination relative to neck axis 16, as have threads 15.

One corner of cap 12 is cut away at 22, as shown in FIG. 1, in order to form in the cap a discharge port 24 which is disposed generally in a surface inclined to the longitudinal axis of the discharge neck, as indicated at 25 in FIG. 2. Both opening 14 and port 24 are located entirely at one side of axis 16 to permit movement into and out of registration. The discharge port 24, although only an opening of little or substantially no axial length through the cap wall, is representative of any type of discharge means in the cap through which the contents of the container may pass to be discharged. Discharge port 24 is so located relative to the opening, 14 that the two are out of registration when the terminal surface is firmly in contact with the mating interior surface on the cap, thus sealing discharge opening 14, as in FIG. 6. A partial turn of cap 12 moves port 24 into registration with discharge opening 14 in the neck, as shown in FIG. 2.

Because of the relatively small amount of axial travel of the interior surface of the cap relative to the terminal surface of the discharge neck as the two surfaces come into contact, turning the cap gives a very high mechanical advantage and the cap and discharge neck surfaces can be brought firmly into engagement with each other with a wedging action which effects a liquid-tight seal by the cap with the exterior surface of the discharge neck entirely around the perimeter of discharge opening 14. In this way, the contents of the container are secured against leakage as well as against contact or contamination with air or foreign matter that may enter the container. This wedging action of the surfaces as they slide over each other to finally close opening 14 is such as to wedge the two members together and hold them against reverse rotation as a result of movement of the container or vibration imparted thereto. Furthermore, it will be seen that a small degree of relative rotation does not necessarily bring the surfaces out of contact with each other, as is the case when the engaging surfaces on the neck and on the cap lies in parallel planes normal to the axis of the threads.

It is preferred to make the cap of a molded plastic that afiords a small degree of elasticity and deformability, as this enables the cap to conform more exactly to the shape of the neck surface 18. The cap, by yielding slightly when turned down tight against the neck, provides a better seal against the surface on the neck. The neck is preferably metal to provide a smooth low friction surface in contact with the cap and allow it to be firmly sealed in the closed position. However, it will be realized that the invention is not necessarily limited to any specific materials or combination.

FIG. 7 illustrates an optional locking means which may be applied to make the cap, when once in place, nonremovable. For this purpose, discharge neck 11 is provided with an external tapered ramp 31 having an inclined forward face and a radial rear face, while cap 12 is provided with an internal tapered ramp 32 which is of similar shape but faces in the opposite direction to ramp 31. Thus as the cap is screwed down clockwise, the two inclined faces of the ramps pass over each other. Upon reverse rotation, the radial faces of the ramps engage each other and prevent rotational movement to an extent that the cap can be removed from the neck. The two ramps are so located that the range of movement of the cap is sufficient to move openings 14 and 24 into and out of registration with each other in order to open and close the container.

FIG. 10 illustrates a variational arrangement of the locking ramps. Here ramps 33 and 34 on neck 11 and cap 12, respectively, are positioned in an axial direction relative to each other instead of in a radial direction in FIG. '7. The inclined surfaces engage and slide over each other on the last turn seating the cap on the neck. With the arrangement of either FIG. 7 or FIG. 10, provision is made for the ramps to pass each other. This may be by a loose fit of the cap on the neck, a looseness that disappears as the cap is tightened; or it may be by selecting a resilient, yielding material for the cap. A plastic, as mentioned above, can accomplish this.

It will be realized from the foregoing discussion that the present invention may be applied to various kinds of containers made of various types of materials and, accordingly, variations in the arrangement and construction of the parts may be utilized. One such modification is shown in FIG. 9 in which the discharge neck 11a is shown as being provided with an opening 35 at the extreme tip of the terminal surface, opening 35 being circular and concentric with the axis of the discharge neck. An opening as at 35 may be provided for any one of a number of purposes, one of which would be to insert a filler tube into the container for the purpose of filling the container after manufacture. By providing at a matching position on cap 120 a circular, coaxial projection 36, the opening 35 may be closed as the cap reaches the end of its downward travel on the neck. Projection 3a: is sufficiently long that it does not disengage the neck during the normal range of movement of the cap to open and close the discharge openings, thus sealing opening 35 at all times.

The presence of projection 36 also has another advantage. It tends to stabilize the position and the movement of cap 12a and thus it may be provided for this purpose alone. A corresponding projection can be provided which would enter the opening 23 to stabilize the terminal position of the cap, even though it is not contemplated that the depression 23 normally penetrates through the Wall of the discharge neck.

An advantageous result of the invention is the unusually high sealing pressure obtained between the terminal surface 18 on the neck and the mating interior surface on the cap. In comparison with a known type of con struction involving a neck of the same diameter with the same threads but without any axial pitch to the sealing surfaces on the neck and cap, it is estimated that the resent construction will generate an axial sealing pressure to 20 times greater. This ensures a tight seal at all times to keep the container contents secure.

It will be apparent that various other changes in the construction and arrangement of the parts constituting the present invention may occur to persons skilled in the art without departing from the spirit and scope of the present invention. Accordingly, it is to be understood that the foregoing description is considered to be illustrative of, rather than limitative upon, the appended claims.

I claim:

1. The combination with a dispensing container, comprising:

a tubular discharge neck having near the outer end thereof a discharge opening communicating with the interior of the container and also having external threads,

said neck having a terminal external surface contoured so that the locus of all points in the surface at a constant radius from the longitudinal axis of the neck is a helix of one revolution having an axial pitch less than the pitch of said threads;

and a cap having an internal surface matching said terminal surface of the neck and internal threads engaging said external threads on the neck,

said cap having discharge passage means movable into and out of registration with said discharge opening by rotation of the cap.

2. The combination as in claim 1 in which the terminal surface on the neck and the matching surface on the cap are curved in axial planes.

3. The combination as in claim 2 in which the discharge opening is in said terminal surface at a position where said surface is inclined to the axis of the neck.

4. The combination as in claim 1 in which the neck has a second opening concentric with the neck taxis and the cap has a pilot pin within and closing the second opening when the cap is seated on the neck.

5. The combination as in claim 1 in which the difference in said pitches equals substantially one thread per inch.

6. The combination as in claim 1 in which the neck is outwardly tapered and the threads are buttress-type threads.

7. The combination with a dispensing container, comprising:

a tubular discharge neck having a terminal external surface curved in axial planes and contoured so that the locus of all points in the surface at a constant radius from the axis of the neck is a helix of one revolution thereby forming an axially extending shoulder in substantially an axial plane,

said neck having an eccentric discharge opening in said terminal surface and having external threads inwardly of said surface of a pitch greater than the pitch of said helix in said terminal surface;

and a cap having an internal surface matching said terminal surface and threads engaging said threads on the neck,

said cap having a discharge port movable into and out of registration with said discharge opening by relative rotation of the cap for less than one revolution.

3. The combination as in claim 7 in which the difference in pitch between the threads and the terminal surface on the neck is less than .01 inch per revolution of the cap.

9. The combination with a dispensing container, comprising:

a tubular discharge neck having near the outer end thereof a discharge opening located entirely at one side of the longitudinal axis of the neck and communicating with the interior of the container,

said neck having external threads and also having a terminal external surface contoured so that the locus of all points in the surface at a constant radius from the longitudinal axis of the neck is a helix of one revolution having an axial pitch less than the pitch of said threads but inclined similarly to the axis of the neck;

and a cap having an internal surface matching said terminal surface of the neck and internal threads engaging said external threads on the neck,

said cap having discharge passage means that is entirely at one side of the longitudinal axis of the neck at the inner end of said passage means whereby said inner end of the passage means is movable into and out of registration with said discharge opening by rotation of the cap.

it). The combination as in claim 7 in which the neck has a second opening concentric with the neck axis and the cap has a pilot pin within and closing the second opening when the cap is seated on the neck, the length of the neck being sufficient that the second opening remains closed at all times by the pilot pin as the cap is rotated to cover and uncover the first mentioned discharge opening in the neck.

References (Iited by the Examiner UNITED STATES PATENTS 2,542,350 2/1951 Paulsen 222-521 X 2,849,166 8/1958 Eitzel 2225 19 2,944,708 7/1960 Smeaton 222-553 LOUIS J. DEMBO, Primary Examiner. 

1. THE COMBINATION WITH A DISPENSING CONTAINER, COMPRISING: A TUBULAR DISCHARGE NECK HAVING NEAR THE OUTER END THEREOF A DISCHARGE OPENING COMMUNICATING WITH THE INTERIOR OF THE CONTAINER AND ALSO HAVING EXTERNAL THREADS, SAID NECK HAVING A TERMINAL EXTERNAL SURFACE CONTOURED SO THAT THE LOCUS OF ALL POINTS IN THE SURFACE AT A CONSTANT RADIUS FROM THE LONGITUDINAL AXIS OF THE NECK IS A HELIX OF ONE REVOLUTION HAVING AN AXIAL PITCH LESS THAN THE PITCH OF SAID THREADS; AND A CAP HAVING AN INTERNAL SURFACE MATCHING SAID TERMINAL SURFACE OF THE NECK AND INTERNAL THREADS ENGAGING SAID EXTERNAL THREDS ON THE NECK, SAID CAP HAVING DISCHARGE PASSAGE MEANS MOVABLE INTO AND OUT OF REGISTRATION WITH SAID DISCHARGE OPENING BY ROTATION OF THE CAP. 